We had a Loki ( AP made) CF handguard installed on my wife's AR, one of the nicest made CF handguards I have seen, the fit and finish is excellent. It is also sturdy, with very little flex. You will save 6-8 oz over a comparable quality aluminum HG.
Loki is a bit backed up at the moment, we have been waiting for the 18" barreled upper for 6 weeks, but all we have heard have been very positive. It will be worth the wait.